This invention relates generally to wireless communications circuitry, and more particularly, to calibrating wireless communications circuitry to allow reduced power consumption.
Handheld electronic devices and other portable electronic devices are becoming increasingly popular. Examples of handheld devices include handheld computers, cellular telephones, media players, and hybrid devices that include the functionality of multiple devices of this type. Popular portable electronic devices that are somewhat larger than traditional handheld electronic devices include laptop computers and tablet computers.
Due in part to their mobile nature, portable electronic devices are often provided with wireless communications capabilities. For example, handheld electronic devices may use long-range wireless communications to communicate with wireless base stations. Cellular telephones and other devices with cellular capabilities may communicate using cellular telephone bands at 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz. Portable electronic devices may also use short-range wireless communications links. For example, portable electronic devices may communicate using the Wi-Fi® (IEEE 802.11) bands at 2.4 GHz and 5.0 GHz and the Bluetooth® band at 2.4 GHz. Communications are also possible in data service bands such as the 3G data communications band at 2170 MHz (commonly referred to as UMTS or Universal Mobile Telecommunications System band). The use of 3 G communications schemes for supporting voice communications is also possible.
To satisfy consumer demand for small form factor wireless devices, manufacturers are continually striving to reduce the size of components that are used in these devices. For example, manufacturers have made attempts to miniaturize the batteries used in handheld electronic devices.
An electronic device with a small battery has limited battery capacity. Unless care is taken to consume power wisely, an electronic device with a small battery may exhibit unacceptably short battery life. Techniques for reducing power consumption may be particularly important in wireless devices that support cellular telephone communications, because users of cellular telephone devices often demand long talk times.
It is important that power reduction techniques for electronic devices be implemented in a way that allows desired performance criteria be satisfied. As an example, many wireless carriers specify required values for adjacent channel leakage ratio (ACLR). High adjacent channel leakage ratio values are an indicator of poor radio-frequency transmitter performance and must generally be avoided to ensure satisfactory network operation. When minimizing power consumption, it would be advantageous to be able to take into account performance characteristics such as adjacent channel leakage ratio performance characteristics, so that improvements in power consumption performance do not inhibit satisfactory wireless performance.
It would therefore be desirable to be able to provide ways in which to calibrate electronic devices with wireless communications circuitry.